[Wetzel]

From what I remember of my chemisty, diffrent lenght hydro-carbon chains burn diffrently. Diffrent ignition temperture as well as burn temp. So if mothballs are indeed naphthalene (C10H8), then it might well burn diffrent then gas. Also, mothballs are solid, arn't they?

But if you have pre-compression ignition, you have other problems you should look into. Like checking that you havn't advanced the timing to far, or if it is just not in time.

Personaly, I'm not sticking mothballs in my gas tank.

Wetzel